The present invention relates to a display unit, and is preferable particularly for use on a display unit capable of displaying image screens having a different aspect ratio each on the same screen.
In a television receiver for NTSC system comprising a screen aspect ratio at 4 to 3, in case, for example, a slight black signal is included in an image high in a mean brightness level like a boundary of a bright background and hair, a black portion of the hair is seen to be afloat visually, and hence proposed hitherto is a black signal correction system for enhancing the black portion of the picture by lowering a level of the black signal.
The black signal correction system comprises detecting the darkest signal level in a video signal, lowering the black signal level to a pedestal level to a thicker visibility.
Meanwhile, it is conceivable that such black signal correction system applied not only to the conventional television receiver but also to a high vision receiver for correcting video signals which may ensure images improved still further.